[Jack-Devel] Patches for jack-0.121-3

Hello all,

I finally found the time to complete and test a set of patches
started more than two months ago, see attachments. These provide:

(jackd/engine.c  jack/internal.h)

   Changes in the DLL implementation and its initialisation.

1. The DLL now has a fixed bandwidth, independent of period
   time.

2. One if its internal variables now represents the current
   best estimate of the actual period time, so this can be
   made available to clients.

3. The DLL is properly reset after freewheeling, so it will
   provide correct information from the first normal cycle.
   Previously this would take more than 10 seconds, with
   'impossible' timing info being provided in the meantime
   - in some cases the period start time would even appear
   to go backwards.

All changes are documented in engine.c. There remain some
open issues which should be reviewed by the regular Jack
devs, please see the comments in engine.c.

(libjack/transclient.c)

4. Fixed jack_time_to_frames() and jack_frames_to_time().
   Both now use signed representation of frames or usecs
   differences internally, ensuring they will return the
   correct result also for events outside the current 
   period.

5. Added jack_get_cycle_times(). This provides atomic access
   to 

   - the frame time at the start of the current period,
   - the microseconds time of the start of the current
     period,
   - the microseeconds time of the start of the next
     period,
   - the current best estimate of the actual period time
     in microseconds.

   All four are just copies of existing DLL variables. 
   This allows clients to convert between frames and usecs
   with full precision. The microseconds times previously
   had to be computed while they were actually available
   internally. 

(jack/jack.h)

6. Added documentation for jack_get_cycle_times().


Everything tested and working to the best of my knowledge.

Ciao,

-- 
FA

Vor uns liegt ein weites Tal, die Sonne scheint - ein Glitzerstrahl.

* Attachment: 'engine.c.diff'
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* Attachment: 'internal.h.diff'
content-type: text/x-diff
* Attachment: 'transclient.c.diff'
content-type: text/x-diff
* Attachment: 'jack.h.diff'
content-type: text/x-diff

1332003748.9588_0.ltw:2,a <20120317170211.GA17438 at linuxaudio dot org>